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Help! A sweet child killed my power amp!

Davegr

May 29, 2011
3
Joined
May 29, 2011
Messages
3
hello! All, a children's theatre group was using my Tascam pa20 b P.A. Amp....and one of the little actors set the script over the cooling vents and the amp overheated and died.
The amp is a stereo ss 20 w per channel or 80w mono bridged. The amp was being used
In bridge mode to power a 10" sub. yeah! It was being pushed a bit for it's size...It is a...
In Tascams ads almost bullit proof. on the front of the amp is circuit protection light
That indicates on overload and will shut the unit off and will reset by itself when the amp
Cools down. I took off the cover and the components I could see didn't look burned ect.
Right next to the power switch is a part that is cube-like with a clear plastic cover and
Relay contacts .I suppose that clicking I've heard a couple times in the past has been
This part when the amp has briefly shut down and reset...SO... My question is could
This part have been totally fried, and the rest of the amp itself is ok?
Right now when it's turned on nothing happens,no hum,no warmth no lights"..This is a
Wonderful transparent amp but it's $ value is right at that point where the cost to have
It fixed is probably not worth it....but if I could get blessed, by one of you experts by
Pointing me in the right direction in finding the bad part...it could LIVE again!
I'm not very knowledgable in electronics but not kind of a do it yourself person and
Am not afraid to take things apart....( I own a fluke mm to use to test parts but am a newbie in using it.) ...the fluke was given to me as broken...resoldered battery lead
And cleaned led display contacts and it worked. Was lucky and it was a fix that helped
Me have hope that with your expertise and direction I might be able to also fix the amp
Thank you in advance for your help Dave.





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Davegr

May 29, 2011
3
Joined
May 29, 2011
Messages
3
Can see no fuse....may be that relay component takes the place of it?
 

Resqueline

Jul 31, 2009
2,848
Joined
Jul 31, 2009
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2,848
No.
There could also be an overtemperature fuse blown, but we've never seen the insides of that amp so posting a nice & sharp picture of it might help.
 

Davegr

May 29, 2011
3
Joined
May 29, 2011
Messages
3
The picture that shows the circuit board has basically 3 main pc boards.The one with
The 2 round black cans is the power pcb.The one with the clear plastic cube,below the power on switch is the phone pcb. The long board connected to the heat sink
Is the amp pcb ...sorry, it's not yet disassembled yet for a better view....

http://i1141.photobucket.com/albums/n585/erin4us/ef0bdbf5.png

http://i1141.photobucket.com/albums/n585/erin4us/1035350f.png

a419abc3.png
 

Resqueline

Jul 31, 2009
2,848
Joined
Jul 31, 2009
Messages
2,848
Ok. If you have an ohm-meter you'll have to measure the resistance in the transformer primary. (That's the brown & white wire.) Keep it unplugged doing this.
No connection (infinite resistance) between those wires means there's a thermal fuse inside the transformer that has blown. Those are hard to get at/ repair.
If there's a low resistance then the fault must be outside - before the transformer, in the mains switch or a mains fuse around there.
 
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